I have noticed that every time I am in the same room as an operating ultrasound machine, I can hear it. And not the machine making noises, but the actual ultrasounds (I know because it decreases in intensity after the gel is added).

'Ultrasound' refers to sound waves with a frequency too high for humans to hear (Wikipedia). Except, it seems, for me.

Simply, my question is, "Is this normal?"

  • 1
    Simple test: did you ask others whether they hear anything?
    – Shlublu
    Apr 28, 2015 at 22:09
  • Yes, but as people get older they can't hear as high of sounds. I asked my mom, dad, and the doctor. (38, 41, and 50+, respectively) None of them could. Apr 28, 2015 at 22:23
  • 1
    what do you mean that it disappears after the gel is added?
    – cnst
    Apr 29, 2015 at 1:02
  • Oh, sorry, it is reduced in intensity or something, not quite sure, but it seems that the gel covers up the noise, because the 'joystick' is the speaker and is being muted of sorts. Apr 29, 2015 at 2:09
  • I find this an interesting question because I can see infrared light and this reminds me of that.
    – L.B.
    Aug 16, 2016 at 17:39

1 Answer 1


It is likely you are not hearing the ultrasound itself (typical frequencies are upwards of 1 MHz, far beyond what the human hearing system is capable of detecting). You are probably hearing coil whine from the electronics -- switched-mode power supplies in particular tend to operate towards the upper end of the hearing range, and the intensity of this sound changes as the power consumption does (eg. when the imaging system goes from "idle" to "active").

  • Is there a way I can test this? Like if I can hear it as soon as the doctor removes it, or would it be going to idle again? Thank you! Apr 29, 2015 at 2:46
  • Depends on the ultrasound machine.
    – Mark
    Apr 29, 2015 at 2:47
  • This has the makings of a great answer, but here on Health, we strongly encourage using references. They are the only way in which we can tell if information is reliable or not. If you are struggling to find good sources, check out, What are reliable sources? If you want to learn more about our site's stance on answers without references, check out, Should answers without references be immediately deleted?
    – Dave Liu
    Feb 12, 2016 at 21:07
  • What about the gel? Aug 31, 2020 at 18:46

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